CLINICAL IMPACT OF ECHOCARDIOGRAPHY IN PROGNOSTIC STRATIFICATION AFTER ACUTE MYOCARDIAL-INFARCTION

Risk stratification is mandatory in the management of the postinfarcti on period. The identification of high-risk patients, on the basis of c linical data (recurrent angina, overt heart failure, etc.), is quite e asy, whereas stratification of uncomplicated subjects needs an accurat e noninvasive strategy. In the last 20 years, echocardiography has bee n gaining an increasing role, allowing increasingly precise evaluation of infarct size. This detection of the extent of infarct size has a d efinite prognostic value. Since 1980, we have observed that a dysfunct ioning left ventricular myocardium >40% marked patients with a poor pr ognosis. These observations are most important in asymptomatic infarct patients, in whom clinical features may not reflect the amount of lef t ventricular dysfunction. Our recent results on a large series of pat ients with acute myocardial infarction (MI) without overt heart failur e have shown that the extension of wall motion abnormalities at 2-dime nsional (20) echocardiography was highly predictive of cardiac death o r new coronary events in a 3-year follow-up (univariate analysis; p <0 .0005). Echocardiography also plays an important role in detecting pos tinfarct ischemia, as seen by its wide use during stress tests. In our experience, the response to exercise echocardiographic testing has a high prognostic value. In fact, in our series, univariate analysis (Ka plan-Meier) showed that the best predictors of coronary events were th e number of markers of ischemia during exercise (p <0.00001), the work load (p <0.00001), a positive exercise echo (p <0.0005), and the echo score at rest (p <0.0005). Multivariate analysis (Cox) confirmed thes e data: number of markers of ischemia: odds ratio (OR) 4.45, 95% confi dence interval (CI) 1.5-13.1;work load: OR 2.46, CI 1.3-4.5; positive exercise echo OR 1.88, CI 1.1-3.2. Thus, serial echocardiography toget her with predischarge stress echocardiography is recommended for risk stratification after acute MI. In particular, in thrombolytic-treated patients, echo examinations allow the detection of functional recovery of viable reperfused myocardium whereas stress echo may show exercise -induced worsening in the region supplied by the infarct-related vesse l, a predictor of a higher rate of coronary events. (C) 1998 by Excerp ta Medico, Inc.